<http://schema.org/alternativeHeadline>
"The 'fascinating' moon Charon likely doesn't have an ocean any longer, but once upon a time, it may have been warm enough to support one."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/space/stories/did-plutos-largest-moon-once-have-a-subsurface-ocean>